


reflection

by bronigiri



Category: Haikyuu!!
Genre: Alternate Universe - Soulmates, Confessions, Getting Together, Growing Up Together, M/M, Sibling Incest, brief Miya Osamu/Suna Rintarou
Language: English
Status: Completed
Published: 2020-11-22
Updated: 2020-11-22
Packaged: 2021-03-09 01:14:39
Rating: Teen And Up Audiences
Warnings: No Archive Warnings Apply
Chapters: 8
Words: 1,600
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/27342577
Author URL: https://archiveofourown.org/users/bronigiri/pseuds/bronigiri
Summary: Atsumu was five years old when he first heard the story that you could see your soulmate every time you looked in a mirror.
Relationships: Miya Atsumu/Miya Osamu
Comments: 32
Kudos: 168





	1. Chapter 1

**Author's Note:**

> Written for Day 1 of Miyacest Week - ‘Soulmate AU’. 
> 
> I wanted to try something new with my writing, so each chapter of this fic is exactly 200 words (a double drabble). :D

Atsumu was five years old when he first heard the story that you could see your soulmate every time you looked in a mirror. In fact, that was how their parents had found each other, too.

When he found out, he ran to the bathroom, tiptoeing so that he could take a look at whoever was lucky enough to spend the rest of their life with him. Only to find that the face that stared back was his own.

_ Well, I figured,  _ Atsumu thought pridefully to himself. He didn’t know too much about  _ love,  _ but it sounded overrated. So long as he had himself, he’d be happy.

“Who’d ya see?” asked Osamu curiously, bouncing on his toes. “What do they look like?”

“I don’t have one,” said Atsumu. His earlier pride is gone, replaced with a sudden trepidation— what if Osamu was the only one who had a soulmate? What if he had to watch Osamu hug and maybe even  _ kiss  _ somebody while Atsumu got… nothing? What if there was something  _ wrong  _ with him? 

“Oh, yeah? Me neither!” Osamu beamed, and raised a fist in celebration.

Something lifted from Atsumu’s chest as he bumped his brother’s fist with his own. 


	2. Chapter 2

Dyeing their hair was Atsumu’s idea. By the time they reached second year of high school, he’d been mistaken for Osamu more times than he could count. Which made no sense, because Osamu was obviously the lesser twin. 

They went to the store and picked out their colours. Atsumu chose blond, and Osamu picked an ugly greyish-brown hue. Their mother bleached their hair for them, and they applied the dye themselves. 

When Atsumu goes to admire his handiwork in the mirror, his stomach drops.

“‘Samu,” he shouts from the bathroom. “What the hell did you put in my dye?”

“I was just goin’ to ask you!”

Osamu hurries up from the downstairs bathroom, footsteps pounding angrily against the floorboards. When he appears at the door, Atsumu points accusingly at the mirror.

“‘Samu! You switched our dyes, didn’t ya?”

Osamu scowls. “I did  _ not.  _ You’re the one who switched ‘em!”

It’s then that Atsumu notices Osamu’s hair is a light brown, the same shade that Atsumu sees reflected back at him. Osamu’s eyes go wide, too, as it sinks in.

“‘Tsumu,” says Osamu. “Your hair’s blond.”

“Yeah?”

“The same shade of blond I see when I look in the mirror.” 

_ Oh.  _


	3. Chapter 3

They don’t tell anybody. They barely talk about it amongst themselves, speaking around it for fear that putting the situation into words would cause irreparable damage. 

“There’s gotta be a glitch in the system,” says Atsumu. “This can’t be— I mean, we’re  _ brothers.” _

Osamu stays silent, picking at a stray thread on the hem of his sleeve. “I didn’t expect this, either,” he says finally. 

“Maybe it’s just because we spend all our time together. Maybe— maybe if we date other people, it’ll change.” Atsumu nods, feeling satisfied with this proposition. He didn’t  _ really  _ believe in fate anyway. If you wanted something, then you worked hard until you got it. If you wanted to be a starting setter, then you trained your ass off until you got the position. Why would soulmates be any different?

“I guess,” says Osamu unenthusiastically.

“C’mon, it’s worth a shot! There’s gotta be somebody out there you have in mind, right?”

When Osamu only shrugs, Atsumu sticks his tongue out at his brother. “Knew it. All ya ever think about is  _ food.  _ Go marry a fuckin’ onigiri, then. See if I care—”

Osamu shoves a pillow into his face, preventing him from saying anything more.


	4. Chapter 4

Atsumu starts going out with a girl from class. She has pretty, short hair, neat handwriting, and nice boobs. Holding her hand feels nice. Kissing her feels— weird, but Atsumu will probably get used to it.

Osamu starts going out with— well. Suna Rintarou, of all people. They do all the things that Atsumu and his girlfriend do, like a pair of creepy copycats: walking home from school hand in hand, making out in front of other people— 

“Jeez, Sunarin, would it  _ kill  _ ya to not gnaw on my brother’s lip in broad daylight? It’s disgusting.”

Suna casts him a sideways look and keeps kissing Osamu. Osamu kisses back like his life depends on it. 

“What’s the big idea?” Osamu prods at him later. “We’re doin’ all the couple-y things you two are doin’. Yer the one who got a girlfriend first. You got a problem just ‘cause mine’s a guy?”

“That’s not—!”

For once, Atsumu is speechless.  _ That’s not the problem,  _ he wanted to say. But that begs the question:  _ what  _ is the problem?

Osamu takes his silence as confirmation, and his face grows cold. “Hypocrite,” he says before stalking off to bed, leaving Atsumu in a confused daze.


	5. Chapter 5

Every day, without fail, Atsumu checks the mirror. Every day, without fail, Osamu glares back at him. 

“Hey,” he asks Osamu one day about a month later. “Did ya look in the mirror recently?”

Osamu makes sure to leave a pronounced delay before he looks up from texting Suna to answer the question. “What’s it to you?” 

“Nothin’. I was just wonderin’ if our plan worked or not.” 

Osamu looks back down at his phone screen and sends Suna a sticker of an adorable cat surrounded by hearts. Atsumu throws up in his mouth a little bit.

“I like him,” says Osamu. “Right now, I want to be with him. The other stuff doesn’t matter.” There’s a coldness in his eyes that’s ever-present lately, and Atsumu hates it. All the time they used to spend together— as brothers, as inseparable companions in life— is now being taken up by Suna.

Atsumu clenches his jaw. “Fine, then.”

Nobody could want to spend  _ forever  _ with Osamu. He drooled when he slept, ate like a pig, and cussed like a sailor when he was mad. Atsumu would just wait and see how long their stupid relationship would last before they burned themselves out. 


	6. Chapter 6

Atsumu wanted to be the first one to go all the way before Osamu and Sunarin got there. But his girlfriend didn’t want to, and when he explained why they absolutely _should_ , she said he had a ‘weird brother complex’ and dumped him on the spot. 

But, like, if anyone asks, Atsumu broke up with her first. At least, that’s what he tells Osamu.

“Nah,” says Osamu. “She totally dumped you.”

“What’s it to _you?”_

Osamu smirks. The first smile Atsumu gets from him in weeks, and it’s this malicious thing that makes his stomach churn. “Nothin’. You totally wanted to win, didn’tcha? But now me and Sunarin are still goin’ steady, and you’re—”

Like a knee-jerk reaction, Atsumu’s fist meets Osamu’s face.

Osamu clutches at his jaw. A vindictive joy thrums through Atsumu’s veins when he sees his split lip. _“What the hell?”_

“Sunarin this, Sunarin that! Will ya shut up about him already— it makes me sick!”

Hurt flickers across Osamu’s face. “Why, because it’s _gay?_ Not that I expected you to have a fuckin’ moral compass, but I thought you’d at least—”

Before he can finish, Atsumu grabs him by the collar and smashes their mouths together. 


	7. Chapter 7

Osamu stumbles backwards, tripping over the edge of the bed and landing on the bottom bunk. 

“What— what’d you do that for?” 

Atsumu touches his mouth. He can taste Osamu’s blood on his lip.

“I don’t hate it ‘cause Suna’s a guy,” he says. “I hate it ‘cause— because I want it to be me, alright?” He clenches his fists, willing them not to shake. “I want to be the one holding your hand, and kissing your stupid mouth, and taking up all your stupid time.”

He flops down next to Osamu on the bed, defeated. So much for not causing irreparable damage. It feels like he’s torn his heart out and tossed it on the ground.

But Osamu’s voice is soft. Hopeful. 

“If you thought that, why didn’t you just say so in the beginning?” 

“Well— because—” Atsumu stammers, fidgeting with his hands. “I’ve never heard of soulmates being brothers. I didn’t think it was possible.”

Osamu smiles. He tilts Atsumu’s chin up with a finger, and kisses him softly on the mouth.

“I still see you,” he says. “When I look in the mirror. It’s always been you, ‘Tsumu.”

Atsumu kisses him back, and it feels like flying.


	8. Chapter 8

“That’s fine,” says Suna when Osamu asks to break up. “I mostly dated you to kill time anyway.” 

Atsumu thinks that’s a shitty thing to say. Then again, he’s done his share of shitty things, so who is he to talk?

“So you don’t see ‘Samu when you look in the mirror?” Atsumu asks, just to be sure.

“Nah,” says Suna. “But Osamu’s nice, and not bad-looking, and shares his food with me.” He sighs. “I’ll miss that.”

“We can still do that,” says Osamu.

Suna casts a dirty look at Atsumu, who’s currently eating the last remains of yakisoba bread out of Osamu’s palm. “No thanks. I don’t want to catch Atsumu germs.” 

Holding hands with Osamu feels better than Atsumu could have ever imagined. Making out does, too. Each time he kisses Osamu, Atsumu feels like his life really  _ does  _ depend on it.

Osamu still drools when he sleeps, eats like a pig, and cusses like a sailor when he’s mad. But his kisses are soft, and he smells like home, and he always makes Atsumu’s favorite onigiri just the way he likes it. So, yeah. Nobody else is allowed to spend  _ forever  _ with Osamu. Nobody but Atsumu.

**Author's Note:**

> Thanks for reading! Feedback is always appreciated <3 
> 
> Find me on [Twitter](http://twitter.com/tsumusamuwu)


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